HU225205B1 - Method for producing tubular containers - Google Patents

Description

In the process, the tubular container is made of a semi-finished product having a neck of a final size and a tubular body of a smaller size than the final. The semifinished product is heated, secured to a pull head (9b) around its neck, introduced by a pull head (9b) into a multi-piece, lockable blow mold (16a), axially pulled by a pull head (9b), and a blower (16) the container lying on its wall is cured, the blow mold (16a) is opened and the container is removed. According to the invention, the tubular container is made of a semi-product having an open filling opening with a flange with a seal at one end and an outward flange at the other end (3), screwing the semi-product to the pull head (9b) and the blowing air it is introduced by means of a nozzle (17) fitted thereon and only the partially inflated or elongated bottom end piece of the container is separated.

The scope of the description is 18 pages (including 13 pages)

Figure 6

HU 225 205 Β1

FIELD OF THE INVENTION The present invention relates to a process for making tubular containers from a semi-finished product having a neck of a final size and a tubular body having a finite size, which is heated to, expanding the inside by blowing air, and then curing the receptacle on the wall of the mold, opening the mold and removing the container, as is known from US-A-4,988,399. In this known process, in a single session, two identical container parts are formed by central separation of a double-sided semi-finished product, and these are then provided with bottoms to form the finished containers.

U.S. Pat. No. 3,855,380 discloses single-piece, seamless compressible tubes, which are manufactured by injection of plastic mass into a confined space.

According to the known process, two identical container parts are produced in one session by separating an intermediate mold made of open preforms on both sides, and then providing both containers with bottoms to produce finished containers.

DE 37 04 264 A1 discloses the production of a hollow plastic body which is open at one end and closed at the other. Here, two completely different techniques, namely injection molding and blow molding, are performed on the same machine; in this regard, it should be borne in mind that injection molding requires considerably longer time than injection molding, which must be taken into account when co-producing on a single machine. A nozzle is used to continuously pull a hose while removing a puller from the plastic-emitting nozzle and slightly inflating the hose with air. Blower air is only introduced to expand the extruded tube section when parts of the adjustable blower mold can be closed, i.e. when there is a sufficient distance between the extraction device and the nozzle supplying the plastic and blowing air.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for the production of tubular, resealable containers which allows simple manufacture of tubular containers of any shape, including a closed dispensing opening.

The object is solved by making the tubular container from a semi-product (preform) having an open filling opening with a flange at one end and a flange at the other end facing the outside, screwing the semi-product to the drawing head, the nozzle is introduced and only the partially inflated or elongated bottom end portion of the container is removed.

Preferably, a metering orifice is formed in the neck of the semifinished product; this step can also be performed after the container has been completed. It is also advantageous to cut the partially formed end piece with a knife or laser beam.

Preferably, the dosing aperture is formed and the partially formed end piece is detached in a single session using a laser beam using light-guiding optics; attaching the neck to the inner thread of the pull head by means of an external thread; heating the semi-finished article to varying degrees along its height and / or circumference.

Radiant heat and / or hot air and / or ultrasound and / or microwaves are preferably used to heat the semifinished product. Axial pulling is preferably carried out by blowing air at a pre-blast pressure of 3-10 bar in two stages and then at an increased blowing pressure of 30-40 bar. After reaching the end position of the nozzle, the nozzle pressure in the blow mold is increased to a maximum of 40 bar. Preferably, a label is inserted into the open die mold.

The invention will now be described in more detail with reference to embodiments and drawings. In the drawings it is

Figure 1: Various semi-finished products with outer flange, a

Figure 2: Semi-finished cross-sections, a

Figure 3: Connecting a semi-finished product to different pulling heads, a

Figure 4: Heating a semi-finished product with radiant heat and hot air, i

Figure 5: Introducing a semi-finished product by means of a pull head into an open nozzle and feeding an air nozzle,

Figure 6: Closing the nozzle mold and then approaching a nozzle to the open end of the semiconductor,

Figure 7: Stretching and pre-blowing a semi-finished product, a

Figure 8: Stretching and blowing of flanged and non-flanged semi-manufactures, a

Figure 9: degassing or venting of the finished container remaining in the blowing mold, a

Figure 10: Opening the nozzle mold and removing the nozzle, a

Figure 11 shows two embodiments for removing only a partially formed end of a finished tubular container, wherein in one embodiment, a through opening is provided in the tube neck simultaneously with removal of the end;

Figure 12: Removing the finished container from the pull head, and

Figure 13: Longitudinal and cross sectional tubular containers.

Figure 1 shows three prefabricated semi-finished products 1. 1a. In Fig. 4, the semi-finished product 1 has a tubular body 2 and an open end 3. At the other end of the tubular body 2, the neck 4 is formed with the final dimensions, which must be adhered to very precisely and reproducibly since this is particularly important for the closure. 1a. In the case of a semi-finished product according to Figs. 1b. The semi-finished product 1 shown in FIG. 2A to FIG

It is noted that a metering opening 7 is centered in the neck 4. 1c. 1A corresponds to FIG. 1a. The neck 4 is closed here but has a conical beak 8.

In the embodiments of Figure 2, the semi-finished articles 1 are circular or oval in cross-section. In addition, rectangular cross sections, such as triangular or polygonal, are possible, preferably with rounded corners (not shown). The wall thickness may be the same across the entire cross-section, or it may be different. For example, it is possible to make a container of oval cross-section and uniform wall thickness from a semi-finished product of circular cross-section and variable wall thickness.

3a. 1a. Figure 1 shows a semi-finished product 1 according to which the draw bar 9a with a pulling head 9b and a two-piece holder 11 can be approached; the latter is also suitable for torque application in a screwdriving process. In this embodiment, the pull head 9b has an internal thread 10 which corresponds to an external thread 5 of the neck 4. The support 11 has a central opening 12, 12 'corresponding to the outer diameter of the tubular body 2 of the semi-finished product. Inside the support portions 11 ', 11' is formed an annular groove 13 for receiving the flange 6 of the semi-product 1. 3b. and 3c. 3b shows possible connections of a semi-finished product 1 with a pulling head 9b: FIG. 3c, the semi-article 1 is fixed and the pulling head 9b is rotatable while the drawing head 3c is rotatable. As shown in Fig. 9, the pull head 9b is non-rotatable and the semi-product 1 is pivotally mounted with the holder 11.

The semi-article 1 fixed on the pulling head 9b is inserted into an optional heater 15, which may also be a heating chamber (Figs. 4a and 4b). The heat source is preferably radiant heat (e.g., infrared radiation), but it is also possible to use hot air, ultrasound or microwave; the heating of the tubular body 2 of the semi-finished product 1 may be uniform or variable along its height and circumference.

In the illustrated embodiment, the heated semi-article 1 fixed to the pulling head 9b is introduced into a two-piece nozzle mold 16 (Fig. 5), the nozzle parts 16 ', 16 "of which enable the flange 6 of the semi-article 1 to Lean on the lower outer end of the 16 blow molds. At the open lower end of the supported semi-article 1, sealed to the flange 6, is fitted a nozzle 17, the diameter of which preferably corresponds to the diameter of the tubular body 2.

As shown in Figure 6, the inner upper end of the closed blow mold 16 is formed according to the outer shape of the pull head 9b, i.e. the pull head 9b forms part of the blow mold 16 in its upper end position.

Fig. 7 shows a transient state of stretching with a pull head upwardly moved in the direction of the arrow and introducing compressed air at a pre-blowing pressure.

In the state shown in Fig. 8, the pull head 9b has already been brought to the upper end position of the nozzle 16 by pulling the pull rod 9a, while the semi-article is preferably stretched at a higher pressure than the pre-blowing pressure; shape. 8b. In Fig. 6b, the nozzle mold 16b has a lower, downwardly opening conical surface 18; this allows the lower open end 3 of a non-flanged semi-article 1 to be secured with a sufficiently conical end outside a nozzle 17 'so that the lower open end 3 of the semi-article 1 cannot move when the nozzle head 9b is drawn in the direction of the arrow.

Figure 9 illustrates the degassing or venting of the finished container through the nozzle 17 provided (see arrows) until the internal overpressure has ceased.

Figure 10 shows the opening of the nozzle mold 16 and the removal of the nozzle 17, whereby due to previous degassing, atmospheric pressure is again inside the molded container 23.

At the lower end of the finished container there is an end piece 19 which is only partially formed, i.e. not completely inflated or elongated, and does not have the desired final dimensions of the produced container. This "incompletely" shaped end piece 19 is cut off with a knife 20 (Fig. 11a) or a laser beam 21 (Fig. 11b). This finished container 23 is also cut to the desired length. The laser beam 21 can be used to form a dispensing opening 7 (dashed arrow) in the closed neck 4 by means of a mirror 22 while simultaneously cutting off the end piece 19; the operations may also be performed by first forming a dispensing opening 7 and then detaching the end piece 19 (drawn arrow). The same applies to the opening of a semi-finished product 1 with a beak 8 (Fig. 1d).

In a further step, relative rotation or opening of the claws between the puller head 9b and the container 23 is removed from the puller head 9b, while a torque holder 11a (Fig. 12a) or a retractable support bar is formed to take in torque. A holder 11b (Fig. 12b) is used to prevent the container from rotating.

Figure 13 shows three different embodiments of the tubular container 23 with three possible cross-sections. 13a. Figure 13b is a circular cross-sectional tubular container; Fig. 13c is an abdominal container of variable height in the direction of the oval; Fig. 4a shows a rectangular container with rounded edges and a recess facilitating the grip of the container. It is also evident from some of the examples presented that the novel process can produce containers of any shape and cross section, with protruding or protruding portions, recesses, gripping surfaces, etc., which greatly extends the field of application compared to conventional tubular container manufacturing methods.

Suitable materials for carrying out the process are PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PÉP (polypropylene), PET / PEN blends and the like.

It is also possible to insert one or more labels in the open blow mold 16a, 16b, which

Finally, they are firmly attached to the finished container 23, which may save the separate labeling process.

In the following, a specific embodiment for making a tube of PET material having a diameter of 50 mm and a length of 200 mm is described. The semifinished 28 mm diameter, 3 mm wall thickness and 66 mm high, smooth or bulging wall is heated to 90-100 ° C, only in the zones where stretching and blowing are required. The tensile stretching is carried out at a speed of 0.3-0.5 m / s while the pre-blowing pressure is 3-10 bar provided by the blower air supplied through the nozzle 17. The semi-finished product is then pressed against the wall of the mold 16a, 16b at an increased pressure of 30-40 bar. At the same time, the blow mold 16a, 16b is approx. It is cooled to 10 ° C, where the cooling time corresponds to an action time of 30 to 40 bar blow pressure. This is approx. 0.8-1.2 s. The finished tube is approx. Bleed for 0.3-0.4 s; the wall thickness of the tube thus produced is 0.15-0.4 mm.

Claims (12)

A method for making tube-shaped containers from a semi-finished article having a final size neck and a tubular body of less than final size, which is heated to a pull head at its neck, introduced into a expanding inside the blower air, then curing the receptacle on the wall of the blow mold, opening the blow mold and removing the container, characterized in that the tubular container (23) is closed at one end and outwardly flanged at the other end (3). is formed from a semi-finished product (1) having an open filling opening, the semi-finished product (1) is screwed to the pull head (9b), the nozzle air is sealed to the open end (3) formed as a filling opening, and Only the partially inflated or elongated bottom end piece (19) of ly (23) is detached. Method according to Claim 1, characterized in that a metering opening (7) is formed in the neck (4) of the semi-finished product (1). Method according to claim 2, characterized in that the dispensing opening (7) is formed after the container (23) has been formed. 4. Method according to any one of claims 1 to 3, characterized in that the partially formed end piece (19) is cut off with a knife (20). 5. A method according to any one of claims 1 to 6, characterized in that the partially formed end piece (19) is separated by a laser beam (21). 6. A method according to any one of claims 1 to 4, characterized in that the production of the dispensing opening (7) and the separation of the partially formed end piece (19) is performed in one session using a laser beam (21) using light-guiding optics. 7. A method according to any one of claims 1 to 3, characterized in that the neck (4) is fixed to the inner thread (10) of the pulling head (9b) by means of an external thread (5). 8. Process according to any one of claims 1 to 3, characterized in that the semi-finished product (1) is heated to different degrees along its height and / or circumference. 9. Method according to any one of claims 1 to 3, characterized in that the semi-finished product (1) is heated with radiant heat and / or hot air and / or ultrasound and / or microwaves. 10. A method according to any one of claims 1 to 4, characterized in that the axial pulling is performed by blowing in two stages with a pre-blow at a pressure of 3-10 bar and subsequently with an increased blow pressure of 30-40 bar. Method according to claim 10, characterized in that after reaching the end position of the pulling head (9b), the blow pressure in the blow mold (16a; 16b) is increased to a maximum of 40 bar. 12. A method according to any one of the preceding claims, characterized in that a label is inserted into the open blow mold (16a; 16b). HU 225 205 Β1 Int Cl .: B29C 49/14 1a. figure 1b. figure 1 c. figure HU 225 205 Β1 Int Cl .: B29C 49/14 3a. figure HU 225 205 Β1 Int Cl .: B29C 49/14 9q : * u * s fe / Λ 3b. figure HU 225 205 Β1 Int Cl .: B29C 49/14 Cl? 4b. figure HU 225 205 Β1 Int Cl .: B29C 49/14 Figure 5 HU 225 205 Β1 Int Cl .: B29C 49/14 Figure 6 Figure 7